This invention relates to an improved process for incinerating chlorinated organic materials, particularly to a method of reducing the level of molecular chlorine in flue gases.
Unwanted chlorinated organic compounds often are formed side by side with useful chlorinated products in many industrial processes. Thus, for example, highly chlorinated butane derivatives and chloroprene polymerization products are obtained as byproducts in chloroprene manufacture. Inactive isomers are formed together with the desired products in the manufacture of chlorinated pesticides, such as, for example, DDT. Because those chlorinated wastes present an environmental hazard, they are normally incinerated.
In the incineration of the usual chlorinated organic wastes, the chlorine is converted mainly to hydrogen chloride, which is scrubbed with water. However, a portion or organic chlorine forms molecular chlorine, Cl.sub.2, which is much less soluble in water than HCl and is not scrubbed efficiently. Some gaseous chlorine is thus present in the flue gas. The presence of this pollutant in the flue gas is, of course, undesirable.
The efficiency of chlorine conversion to hydrogen chloride can be improved, for example, by injection of superheated steam into the incineator's combustion zone. This prior art method suffers from the drawback that steam injection into the combustion zone tends to lower the incinerator's temperature, so that additional energy is required to maintain the required temperature level. Furthermore, the presence of steam in the combustion zone reduces the effective volume of the incinerator and thus its throughput. Finally, it accelerates corrosion and breakdown of incinerator materials, including the refractory lining of the combustion zone.
It can be readily seen that more efficient methods of incinerating chlorinated organic materials are desired.